We explore some misconceptions about statistical mechanics that are, unfortunately, still current in undergraduate physics teaching. The power of the Gibbs ensemble is emphasized and explained, and the second law of thermodynamics is proved, following Jaynes (1965). We then study the crucial role of information in irreversible processes and demonstrate by means of a concrete example how time-dependent data enable the equilibrium Gibbs ensemble to predict time-varying fluxes during the return to equilibrium.

Biography: Professor Steve Gull has been at the forefront of developments in maximum entropy techniques since the mid-1970s. His research in radio astronomy lead him to develop very general techniques for image reconstruction from noisy data. He is a director of the spin-off company (Maximum Entropy Data Consultants) which commercialises these techniques for real-world problems.